function get_css(rule_name, stylesheet, delete_flag) {
    if (!document.styleSheets) return false;
    rule_name = rule_name.toLowerCase();
    stylesheet = stylesheet || 0;
    for (var i = stylesheet; i < document.styleSheets.length; i++) {
        var styleSheet = document.styleSheets[i];
        css_rules = document.styleSheets[i].cssRules || document.styleSheets[i].rules;
        if (!css_rules) continue;
        var j = 0;
        do {
            //if(i == 2 && j > 30) alert(css_rules[j].selectorText.toLowerCase() + " " + rule_name);
            if (css_rules.length && j > css_rules.length + 5) return false;
            if (css_rules[j].selectorText && css_rules[j].selectorText.toLowerCase() == rule_name) {
                if (delete_flag == true) {
                    if (document.styleSheets[i].removeRule) document.styleSheets[i].removeRule(j);
                    if (document.styleSheets[i].deleteRule) document.styleSheets[i].deleteRule(j);
                    return true;
                }
                else return css_rules[j];
            }
        }
        while (css_rules[++j]);
    }
    return false;
}
function add_css(rule_name, stylesheet) {
    rule_name = rule_name.toLowerCase();
    stylesheet = stylesheet || 0;
    if (!document.styleSheets || get_css(rule_name, stylesheet)) return false;
    (document.styleSheets[stylesheet].insertRule) ? document.styleSheets[stylesheet].insertRule(rule_name + ' { }', 0) : document.styleSheets[stylesheet].addRule(rule_name, null, 0);
    return get_css(rule_name, stylesheet);
}
function get_sheet_num(href_name) {
    if (!document.styleSheets) return false;
    for (var i = 0; i < document.styleSheets.length; i++) {
        if (document.styleSheets[i].href && document.styleSheets[i].href.toString().match(href_name)) return i;
    }
    return false;
}
function remove_css(rule_name, stylesheet) {
    return get_css(rule_name, stylesheet, true);
}

function add_sheet(url, media) {
    if (document.createStyleSheet) {
        document.createStyleSheet(url);
    }
    else {
        var newSS = document.createElement('link');
        newSS.rel = 'stylesheet';
        newSS.type = 'text/css';
        newSS.media = media || "all";

        newSS.href = url;
        // var styles	= "@import url(' " + url + " ');";
        // newSS.href	='data:text/css,'+escape(styles);
        document.getElementsByTagName("head")[0].appendChild(newSS);
    }
}